The doctors tapped by the federal government to medically screen immigrants seeking green cards include dozens with a history of “egregious infractions,” according to a report from a federal watchdog agency.

The report looked at more than 5,500 doctors across the country used by United States Citizenship and Immigration Services as of June 2017 to examine those seeking green cards. More than 130 had some background of wrongdoing, including one who sexually exploited female patients and another who tried to have a dissatisfied patient killed, the report said.

The report, made public Tuesday by the Department of Homeland Security’s Office of Inspector General, said the failure to effectively screen the doctors put immigrants “at risk of abuse.”

“USCIS is not properly vetting the physicians it designates to conduct required medical examinations of these foreign nationals, and it has designated physicians with a history of patient abuse or a criminal record,” the report states. “This is occurring because USCIS does not have policies to ensure only suitable physicians are designated.”

Alma Rosa Nieto, an immigration lawyer and vice chairwoman of the American Immigration Lawyers Association’s media advocacy committee, called the report’s findings “very troubling and frightening,” particularly given that the people undergoing the examinations are vulnerable.

“These are people that are in great need,” she said. “They are desperate to get their green card.”

Doctors must apply to be part of the government’s pool of screeners. Once approved, they conduct the mandatory medical exams for immigrants who are looking to become permanent residents and get green cards. Immigrants can be turned down if they are found to have a disease that could be a public health threat, have a mental disorder that could threaten others or are drug addicts.

The report did not identify the doctors who engaged in misconduct, nor did it reveal whether they are still on the government’s approved list.

The director of United States Citizenship and Immigration Services, L. Francis Cissna, told the Office of Inspector General that the agency was working to address the report’s concerns, and that “further actions are needed,” according to a spokeswoman.

A spokeswoman for the Office of Inspector General declined to comment further on the report Wednesday.

From a total pool of 5,569 doctors, 132 had been convicted of crimes, been penalized by state medical boards or had faced some other form of punishment, the report found. They included doctors convicted of health care fraud, doctors who had defaulted on health education loans or scholarships and doctors “engaged in dishonest, gross, and repeated negligent conduct in patient care and treatment.” It did not give a specific breakdown.

In a sample of 135 physicians, 14 percent were missing required papers, including proof of medical degrees.

“To guard against risking the health and safety of these foreign nationals, USCIS should more thoroughly scrutinize physicians before allowing them to become civil surgeons,” the report advises.

The report also found fault with the medical tests themselves, saying they possibly exposed the public to health hazards. An analysis of 151 files of immigrants approved for green cards found errors in 44 forms, such as missing proof of vaccinations or required medical tests.

“As a result, USCIS cannot be certain the civil surgeons actually administered all required tests and vaccinations and may have granted lawful permanent residence status to medically inadmissible foreign nationals who could pose a health risk to the U.S. population,” the report said.

Ms. Nieto said that she was not surprised at the findings, and that her clients routinely had errors in their files. She said she advised clients to get independent medical tests done, if possible, even if it costs extra money and time.

“I see my clients coming back with reports that are either incomplete or inaccurate,” she said.